Parallelism is widely seen as a key to enhancing computer performance in the future. Interconnection of the many processors or memory units is a major obstacle to achieving this result. Conventional crossbar switches are impractical because the number of switches required grows as the square of the inputs.
One of the features of the present invention is directed to an electron beam crossbar in which an array of electron emitters may be independently directed to communicate with any selected one or more of an array of receivers. The electron beam crossbar switch provides easily steerable beams, delivers the source power to the detectors with minimal stray current, and most importantly provides the ability to transmit data via beams of electrons through free space without using wires. The use of an array of electron beams to perform a crossbar switching function appears to be highly advantageous in solving the problem of a large number of processors, for example, as many as 1000.
However, the present invention is useful in other applications besides a crossbar switch such as an encoder/decoder in which data might be scrambled by a rapidly programmable permutation; and for various matrix operations, such as transposing rows and columns. Furthermore, the present invention is not limited to the use of electrons, but to other types of electric beams such as electrically charged particles such as protons and ions.